Series lamp socket



Aug. 11, 1936. J. F. MORTON I SERIES LAMP SOCKET Filed Deo. 18, 1934 M L@ @y 6 INVENTOR L/f? FM/ON Patented Aug. 1l, 1936 UNITED STATES PATENT QFFICE SERIES LAMP SOCKET Pennsylvania Application December 18, 1934, Serial No. 758,017

12 Claims.

My invention relates, generally, to lighting apparatus, and, more particularly, to lamp sockets for use in circuits where it is desired to maintain the circuit regardless of the condition of the lamp.

In the operation of some lighting systems, and especially, series street lighting systems, it is desirable to provide for automatically shunting or short-circuiting the socket and lamp in the event of lamp failure.

Various devices have been provided for accomplishing this, among them being lm cutouts and other forms of cutouts or short-circuiting devices which function in response to a predetermined increase in voltage resulting from lamp failure and which must be renewed or replaced after each operation.

It is the object of my invention, generally stated, to provide a lamp socket which shall .be of simple construction, efficient in operation, inexpensive to manufacture and install and which shall be safe and economical to use.

A more speciiic object of my invention is to provide a lamp socket adapted for use in series lighting circuits and the like, which embodies a cutout or short-circuiting device which functions in response to lamp failure and which may be reset or reconditioned by the operation of replacing the lamp.

A further object of my invention is to provide for short-circuiting a lamp socket in response to lamp failure and for maintaining the short-circuited condition until the lamp is removed from the socket and replaced.

Another object of my invention is to provide for reconditioning a cutout device by the removal of the lamp from the socket.

A still further object of my invention is to provide for utilizing the movements of one of thel contact members of a lamp socket for controlling the functioning of a cutout or short-circuiting device used therewith.

Another object of my invention is to provide a combination lamp socket and cutout device of such nature that the cutout device is automatically reconditioned for operation in response to the removal of the lamp from the socket.

Still another object of my invention is to provide a cutout device for use with lamp sockets which does not require the replacement of new elements after each operation or its removal from the lighting unit in order to recondition it for a subsequent operation.

These and other objects and advantages of my invention will become apparent imm the follow- (Cl. G-118) ing detailed description thereof, when read in conjunction with the drawing in which:

Figure 1 is an elevational View, partly in section, of a lamp `Socket embodying the principal features of the invention,

Figs. 2 and 3 are enlarged views showing the cutout reconditioning device in different positions, and

Fig. 4 is a View showing a modified form of cutout device.

Referring now to the drawing, there is illustrated in Fig. 1, one embodiment of the invention in the form of a lamp socket for use in series lighting systems where it is desired to prevent any interruption of the circuit in the event of failure of one or more lamps.

The device as illustrated comprises a body member or base I0 of the usual socket shape composed of porcelain, moulded material, or the like, having a suitable depression II therein in which is mounted a stationary contact member I2 in the form of a threaded shell disposed to receive the base of a lamp (not shown) and a movable central contact member I3.

The contact members I2 and i3 may be connected to the circuit by means of the terminal bolts I4 and I5, respectively, the bolt I4 being connected directly to the contact shell I2 and the bolt I5 being connected to the center contact I3 by means of a flexible connector IB in order to permit this contact member to be moved relative to the base for a purpose which will appear more' fully hereinafter.

In this embodiment of the invention, the cutout or short circuiting device comprises a pair of spaced contact elements II and I8, compo-sed of any suitable metal, such, for example, as lead, which are supported from thebase IE) of the socket by means of prongs I9 secured to the terminal bolts I4 and I 5, as shown. The contact elements I'I and I8 are held in spaced relation to provide an arcing space or air gap by means of insulating Washers 2| and 22 which are secured to the lower ends of the prongs I9 in any suitable manner and a spacer 23, the washers and spacer being held together by means of suitable rivets 2li as shown in Figs. 2 and 3. As shown in Figs. 1, 2 and 3 of the drawing, the rivets 23 are positioned a sufficient distance from the contacts Il Vand IS as to clear the flat parallel faces of the prongs I9 to avoid any possibility of short circuiting the prongs.

As it will be readily understood, the cutout is connected to the line circuit in parallel relation to the contact members I2 and I3 of the lamp socket, the spacing between the contact elements il and I8 of the cutout being such that an arc will be established therebetween in response to a predetermined increase in voltage across the socket terminals such as would result upon the failure of the lamp. This arcing causes the formation of a point contact between the con tact members il and i8, such that they are fused together to effectively short circuit the contact members i2 and i3 of the socket.

In order toy provide for reconditioning the cutout without removing the cutout or the socket from the lighting fixture provision is made for automatically separating the contact elements il and i8 and thereby re-establishing the air gap in response to the removal of the lamp from the socket.

In this instance, this function may be performed by a metallic tongue 24 which is connected to the movable center contact i3 by means of a sha-ft which extends through a suitable opening in the bottom of the base member it), as shown, the other end of which is 'positioned between the insulating washers 2i and 22 of the cutout. This end of the tongue is provided with an opening 26 which is of somewhat larger diameter than the arcing face of the contact elements i'l and l, and winch isrpositioned directly opposite these contact elements when the center contact member i3 is in its fuliy depressed position..

In order that the operation of the tongue 2d to recondition the cutout may be efected automatically in response to the removal of the lamp which has failed, the center contact member i3 is provided with a suitable biasing spring fil which functions to bias the contact member to its upper position, as shown in Fig. l.y It will be apparent that upon the removal of the lamp from the socket Contact member i3 is forced upwardly by the spring 2li, thereby causing the tongue 2d to be moved upwardly between the contact elements il and i@ of the cutout to the position as shown in Fig. 3.

The movement of the tongue 2d to its upper position effectively re-establishes the spacing or air gap between the arcing faces of the contact elements and iii, thereby reconditioning the cutout for a subsequent operation.v The tongue 2d also performs the function of effectively shortcircuiting the lamp socket until the center contact member i3 has been again depressed to its lower position, thereby positioning the tongue as shown in Fig. 2. This is accomplished because of the fact that the lower tip 2S of the tongue remains in contact with the arcing faces of contact elements il! and I8 at all times after the center contact member I3 has been released until it is again depressed. Therefore, it is evident that the lighting circuit is automatically maintained while the lamp which has failed is being replaced and the cutout reconditioned for a subsequent operation.

In Fig. 4. there is shown a slightly modified form of cutout device which may be formed as a unit supported by the prongs i9. In this embodiment the contact elements 29 and 30, of lead or other suitable material, may be secured to the insulating plates 3i and 32 and these plates together with the spacer 33 secured together as a unit by means of suitable rivets similar to the embodiment shown in Figs. 2 and 3. The contact members 29 and 3) extend o-utwardly from the surface of the insulating plates to provide connecting elements disposed to engage with suitable openings in the prongs i9 to support the cutout element from the socket.

As will be readily understood the cutout element may be readily removed by spreading the prongs i9 in the event that it should become damaged.

In view of the foregoing, it is now apparent that I have provided a combination socket and cutout of a very simple construction, which may be used over and over again without requiring the removal of the socket from the lighting Xture or the replacement of any parts following each lamp failure.

Since certain changes may be made in the above construction andv different embodiments of the invention may be made without departing from the spirit thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

l. In combination, a lamp socket having a contact element disposed to receive a lamp base, and a cutout device connected to the socket and operable when subjected to a predetermined voltage to short-circuit the socket, said cutout device being operable in response to the removal of the lamp base from the socket to recondition itself for a subsequent operation.

2. In combination, a lamp socket having a contact element disposed to receive a lamp base, and a cutout device connected to the socket and operable when subjected to a predetermined voltage to short-circuit the socket, said cutout device comprising spaced contact elements and a movable element positioned therebetween and actuated in accordance with the insertion and removal of the lamp base into and out of the socket.

3. In combination, a lamp socket having a movable contact member actuated by the removal and insertion of a lamp base, a cutout device connected with-the socket operable in response to lamp failure to short circuit the socket, and means actuated by the movable contact member upon the removal of the lamp for reconditioning the cutout device and by the insertion of a lamp for again rendering the cutout device operable to short circuit the socket.

4. In a lamp socket, in combination, a base, a stationary terminal mounted on the base adapted to receive a lamp base, a movable terminal normally biased to one position and disposed to be actuated to a different position by the insertion of the lamp base into the stationary terminal, ycutout means supported by the base adapted to function in response to lamp failure, and means actuated by the movable terminal upon removal of the lamp base for reconditioning the cutout means for operation and for rendering the cutout means effective upon the insertion of a lamp base into the socket.

A lamp socket comprising a stationary contact member disposed to receive a lamp base, a movable contact member actuated in one direction by the insertion of a lamp base into the stationary contact member and in another direction in response to the removal of the lamp .from the socket, a cutout device connected in parallel With the contact members of the socket, and means actuated in accordance with the movements of the movable contact member for rendering the cutout device effective to shunt the stationary and movable contact members upon failure of the lamp and to recondition the cutout device in responsive to the removal of the lamp from the socket.

6. A lamp socket comprising a stationary contact member disposed to receive a lamp base, a movable contact member actuated in one direction by the insertion of a lamp base into the stationary contact member and in another direction in response to the removal of the lamp from the socket, a cutout device connected in parallel With the contact members of the socket, and means actuated in accordance with the movements of the movable contact member for rendering the cutout device eiective to shunt the stationary and movable contact members upon failure of the lamp and to recondition the cutout device in response to the removal of the lamp from the socket, said means being disposed to cooperate with the cutout device to maintain a shunting circuit across the stationary and movablel contact members dependent upon the removal of the lamp base from the socket to a predetermined degree.

7. A lamp socket comprising a stationary contact member disposed to receive a lamp base, a movable contact member actuated in one direction by the insertion of a lamp base into the stationary contact member and in another direction in response to the removal of the lamp from the socket, a cutout device connected in parallel with the contact members of the socket, said cutout device having spaced contact elements disposed to become fused together in response to failure of the lamp, and means actuated by the movable contact member in response to the removal of the lamp from the socket for reestablishing the spacing of the contact elements of the cutout device and for maintaining them connected together until a lamp base is inserted into the socket.

8. A lamp socket comprising a stationary contact member disposed to receive a lamp base, a movable Contact member actuated in one direction by the insertion of. a lamp base into the stationary contact member and in another direction in response to the removal of the lamp from the socket, a cutout device connected in parallel With the contact members of the socket, said cutout device having space-d contact elements disposed to become fused together When subjected to a predetermined voltage resulting from a failure of the lampy in the socket, and a tongue member actuated in accordance With the movements of the movable contact member of the socket disposed to reestablish the original spacing of the contact elements of the cutout device.

9, A lamp socket comprising a base, stationary serted into the socket and for reconditioning the cutout device for operation When the lamp base is partially removed from the socket.

1G. A lamp socket comprising a base, stationary and movable terminal members mounted in the base, said stationary terminal member being disposed to receive a lamp base, a cutout device supported by the base, said cutout device comprising spaced contact members connected in parallel-circuit relation with the lamp carried by the socket and disposed to become joined together on failure of the lamp, and means actuated by the removal of the lamp from the socket for separating the contact members of the cutout device.

11. A lamp socket comprising a base, stationary and movable terminal members mounted in the base, said stationary terminal member being disposed to receive a lamp base, a cutout device supported by the base, said cutout device being operable to short-circuit the contact members of the socket upon failure of the lamp, and means 12. In combination, a lamp socket provided" with a stationary contact member disposed to receive a lamp base and a spring biased movable contact member disposed to be depressed in response to the insertion of a lamp base into the socket, a cutout device comprising spaced contact elements connected to the socket contact members and disposed to become connected together to short circuit the socket contact members in response to an arc formed therebetween on failure of the lamp, and a metallic member connected to the movable contact member having an opening in one end thereof which is positioned opposite the contact elements .of the cutout device when the movable contact member is depressed by the lamp base and which is moved relative to the contact elements of the cutout when the lamp base is removed from the sock-et, thereby to recondition the cutout device for a subsequent operation.

JOHN F. MORTON. 

